Research on single-parameter continuous gradation equation considering fine particle content
The fine particle effect of sands has a significant impact on its physical and mechanical properties,but the existing gradation equations are difficult to accurately quantify the fine grain content of sands.To more quantitatively characterize the gradation characteristics and fine particle content of sands,a single-parameter continuous gradation equation considering the fine particle content fc was proposed.The reflective ability of this gradation equation on the characteristics of sands gradation curves was analyzed,and its applicability to different types of sands gradations was demonstrated.Meanwhile,relationships of non-uniformity coefficient Cu and curvature coefficient Cc in regards to the grading equation parameters(characteristic parameter m,fine particle content fc and maximum particle size dmax)were established,based on which,the gradation experiment design of sands was conducted.The main conclusions are as follows:1)The proposed single-parameter continuous gradation equation can not only fully reflect the three typical forms of gradation curves which are reversed S-shaped,approximate straight line shape and hyperbola,but also accurately quantify the gradation characteristics and fine particle content of sands,thus providing better applicability than the existing continuous gradation equation.2)When dmax is known,by adjusting the combination of m and fc,the single-parameter continuous gradation equation can regulate the form of the gradation curve,characteristic particle size dP,Cu and Cc,so as to meet the requirements of sand gradation for engineering construction.3)By utilizing the relationship equations between Cu and Cc and the parameters of the gradation equation,the value ranges of m and fc under well-graded conditions of sands can be derived,which can rapidly distinguish the gradation quality of sands.4)The single-parameter continuous gradation equation can be used to design a series of gradation curves with specific gradation characteristic parameter values or value ranges,which is more accurate and efficient than traditional methods.The research conclusions can provide a theoretical basis for further quantifying the influence of sand gradation characteristics and fine particle effect on its relevant physical and mechanical properties.
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维普
